Recently, electric vehicles are emerging as a solution to societal problems such as the implementation of environmentally friendly technologies and energy depletion. An electric vehicle operates using a motor that receives electricity supplied from the battery and outputs power. Therefore, there is no emission of carbon dioxide, the amount of noise is very small, and the energy efficiency of the motor is higher than the energy efficiency of an engine, and thus, the electric vehicle is attracting attention as an environmentally friendly vehicle.
The key technology for implementing such an electric vehicle is the technology related to a battery module. Recently, research toward the weight reduction, miniaturization, and reduction in charging time of a battery has been actively carried out. The battery module can maintain optimal performance and a long service life when used in an optimal temperature environment. However, it is difficult to use in the optimal temperature environment due to the heat generated during driving and external temperature changes.
In addition, since the electric vehicle does not have a waste heat source for the heat generated during the combustion in a separate engine, such as in the case of an internal combustion engine, it is necessary to perform indoor heating of the vehicle in the winter using an electric heating device and to perform warm-up in order to improve the charge and discharge performance of the battery during a cold period. Therefore, a separate coolant heating electric heater is individually configured and used. That is, in order to maintain the optimal temperature environment of the battery module, a cooling and heating system for controlling the temperature of the battery module is adopted separately from a heating and cooling system for indoor HVAC of the vehicle. In other words, two independent cooling and heating systems are built, one of which is used for indoor cooling and heating, and the other of which is used for temperature control of the battery module.
However, when the cooling and heating systems are operated as described above, it is impossible to efficiently manage energy. Thus, the traveling range of the vehicle is shortened, which makes long-distance operation impossible. When cooling is performed in summer, the traveling range may be reduced by 30% or more, and when heating is performed in winter, the traveling range may be reduced by 40% or more. Therefore, the winter heating problem, which is not a problem affecting internal combustion engines, becomes more serious in electric vehicles. When a high-capacity PTC heater is installed to solve the problems caused by heating in winter, the cost and weight may become excessive due to the reduction of traveling range and the use of a heat pump.
It should be understood that the foregoing description of the background art is provided merely for the purpose of promoting the understanding of the background of the present disclosure, but is not intended to acknowledge that the present disclosure corresponds to the prior art that has already been known to those skilled in the art.